Yes, most wood fireplaces and many gas fireplaces will heat your home during a power outage. An open masonry fireplace, a freestanding wood stove, and a wood insert all burn without electricity, though the insert loses its blower. A gas fireplace with a standing pilot and a millivolt valve runs with no power at all, and most newer electronic ignition units have a battery backup for exactly this situation. Pellet stoves are the exception. Without power, most of them are cold steel.
The catch is that "will it light" and "will it warm the house" are two different questions. An open fireplace pulls a large volume of heated room air up the flue, so it can warm the room you are sitting in while quietly cooling the bedrooms down the hall. And the moment people start improvising for heat, carbon monoxide becomes more dangerous than the cold.
We have worked through enough Front Range storms, from March blizzards to public safety shutoffs, to know what actually helps. Here is what works, how to run it, and how to prepare so the first cold night is not the night you learn your damper is stuck.
Which Fireplaces and Stoves Work Without Electricity
Two columns matter most: whether it will light at all, and how much useful heat to expect.
Table 1. How common fireplaces and stoves behave during a power outage.
| Appliance | Works without power? | Useful heat | What changes in an outage |
|---|---|---|---|
| Open wood burning fireplace | Yes | Low, radiant heat near the hearth | Nothing mechanical to lose, but it draws a lot of room air |
| Freestanding wood stove | Yes | High | Optional blower stops. The stove body keeps radiating. Best outage performer of the group |
| Wood insert with blower | Yes, but the fan stops | Moderate, drops without the fan | Burn at a moderate rate and check the manual for limits on running without the blower |
| Radiant wood insert, no blower | Yes | Moderate | No change. Designed to work by radiation alone |
| Gas fireplace, standing pilot, millivolt valve | Yes | Moderate | Switch, thermostat and remote still work because the pilot makes its own tiny current. Blower stops |
| Gas fireplace, electronic ignition with battery backup | Yes, if the batteries are fresh | Moderate | Batteries power the control module and igniter. Dead batteries mean no fire |
| Gas fireplace, electronic ignition, no backup | Usually not | None | Some models allow a manual pilot mode. Check the manual before you need it |
| Pellet stove | Usually not | None without power | Needs power for the auger, igniter and exhaust fan. A battery backup or a generator through a transfer switch can run it |
| Vent free gas logs or heater | Yes | High | All combustion moisture and exhaust stays in the room. Built for limited run time, not days in a sealed house. Crack a window, run a CO alarm, never sleep with it on |
A wood stove owner is in the best position. An open fireplace owner can stay safe and reasonably comfortable by managing the house around it. A gas fireplace owner should spend ten minutes this month finding out which kind they have, because that decides whether it lights on a dark night in January. Pellet stove owners should read the outage section of our pellet stove guide for Colorado before deciding on a battery backup.
The Honest Heat Math for an Open Fireplace
An open masonry fireplace is a beautiful thing and a poor furnace. Typical figures put its efficiency around ten percent or less, because it pulls heated room air up the flue and drags cold air in through every gap in the rest of the house. Our guide on getting more heat from your fireplace explains where the heat goes and the free fixes for it. For an outage, the short version is to treat it as a one room heater and manage the house around it, which is what the rest of this article is about.
Carbon Monoxide Rules That Matter Most When People Improvise
The calls we hate come after a storm, when someone got cold and brought something inside that was never meant to burn indoors. Carbon monoxide is odorless and builds fastest in a closed up house with no fans running.
- Never run a grill, camp stove, patio heater or generator indoors. That includes the garage with the door open and the covered porch. Charcoal is the worst offender.
- Generators go outside, at least 20 feet from any window, door or vent, with the exhaust pointed away from the house.
- Battery powered CO alarms on every level. Hardwired alarms with a dead backup battery go silent exactly when you need them. Colorado has required CO alarms near bedrooms in homes with fuel burning appliances at sale or rental since 2009, but the battery is on you.
- Crack a window when you burn in a tight house. Newer builds in Central Park and the south suburbs are sealed well enough that a fire can starve for air and spill smoke and CO into the room. An inch near the fireplace is plenty.
- Know the symptoms. Headache, nausea, dizziness, confusion, and everyone in the room, pets included, feeling sick at once. Get outside, then call for help.
- Never close the damper to save heat while coals still glow. Coals produce CO for hours after the flames die.
Our guide to carbon monoxide and chimney safety in Colorado covers where alarms belong, what to do when one sounds, and how a blocked flue causes trouble in normal weather. In an outage, put a CO alarm in the room where the fire is.
Running a Gas Fireplace When the Power Is Out
Gas fireplaces come in two control families, and knowing which you have is most of the battle. The notes below are general, and your manual wins any disagreement.
Standing pilot and millivolt valves
If a small pilot flame burns all season, you almost certainly have a millivolt system, and an outage changes nothing but the blower. If the pilot is out, the relighting sequence is printed on the rating plate. For how the thermopile and valve work together, and what to do when the pilot will not stay lit, see our guide to gas fireplace pilot light problems.
Electronic ignition and the battery backup
Newer units use intermittent pilot ignition. There is no pilot flame between fires. A control module sparks the pilot, proves it is lit, then opens the main valve. That module normally runs on household power, and most include a battery holder, typically four AA or D cells, that takes over when the power fails. The batteries run the brain and the spark, which is all you need for heat.
Replace the backup batteries every fall, follow your manual on removing them in summer since heat in the control compartment can cause leaks, and test the fireplace in October by switching off its breaker and lighting it. Some units also offer a manual pilot mode for dead batteries. If yours has no backup and no manual mode, it is not an outage heater.
What not to do with a gas unit
Never bypass a safety valve, never light a main burner with a match, and never run a gas fireplace with the glass removed. If you smell gas, leave and call the utility from outside. Our fireplace repair and installation crew handles gas units across the metro, and if you have thought about converting an open fireplace to a sealed gas insert, outage performance is one of the better arguments for it.
Keeping One Room Warm: The Order of Operations
Once the fire is going, the rest is house management. Do these in order.
- Pick the fireplace room and close every door to it. You are heating a box, so make the box small.
- Block the drafts. Rolled towels under doors and drapes closed at night. On a sunny Colorado day, open the south facing curtains and close them before dusk.
- Hang blankets over open doorways and big windows. A quilt on a tension rod across a cased opening works well.
- Run the fire steadily rather than in bursts. A hot flue drafts well and a warm firebox keeps radiating. Letting the fire die and restarting it every few hours means a cold chimney, a smoky start and more creosote.
- Rotate the wood. Bring the next two loads inside so they warm up and shed surface moisture before they hit the grate.
- Crack a window an inch near the fire if the house is tight or the fire is sluggish. The fire needs that air and will otherwise pull it through the cold end of the house.
- Gather everyone in the warm room and keep a fire watch. Someone stays awake while flames are up. At bedtime, let the fire burn down to coals behind a closed screen, damper open.
Frozen Pipes and the Fireplace as a Tool
The fireplace room will be fine. The pipe on the north wall behind the kitchen sink, or the line through an unheated crawlspace in an Arvada ranch, is the real risk once the house drops into the 30s. Open cabinet doors under exterior wall sinks, let a cold tap drip, and know where the main shutoff is. A central masonry chimney warms the rooms around it, one reason old Denver floor plans wrapped the kitchen and bath around the chimney. Never use an open flame to thaw a pipe, not a torch, not a candle, not a pan of coals. In a long outage the safer move is often to shut off the main and drain the lines, then let the fireplace keep the people warm while the pipes sit empty.
What Not to Burn When You Are Desperate for Fuel
On the second night, the woodpile looks smaller and the broken chair in the garage starts to look like fuel. Do not do it. Most of what people reach for poisons the room, damages the flue, or starts a chimney fire, and a chimney fire with no power is a very bad night.
Table 2. Common emergency fuels, the problem with each, and what to use instead.
| Material | Why it is dangerous | Better choice |
|---|---|---|
| Pressure treated lumber, deck boards, fence posts | Copper and other preservatives become toxic in smoke and ash | Untreated scraps, kiln dried offcuts |
| Painted, stained or finished wood | Chemical fumes, older paint may contain lead | Bare hardwood or pine splits |
| Furniture, plywood, particleboard, pallets | Glues and resins produce toxic smoke, some pallets carry chemical treatments | Dry cordwood, or one manufactured fire log at a time in an open fireplace |
| Charcoal briquettes | Enormous carbon monoxide output, deadly indoors even in a fireplace | Never indoors, in any appliance |
| Trash, plastic, glossy paper, piles of cardboard | Flash burning sends flames and fragments into the flue, plastics release toxins | A few sheets of plain newspaper for kindling only |
| Christmas tree, pine boughs, wreaths | Explosive flare, heavy sparking, fast path to a chimney fire | Split softwood kindling in small amounts |
| Wet or green wood | Smolders, heavy smoke and creosote, little heat | Wood seasoned to 20 percent moisture or less |
| Gasoline, kerosene, lighter fluid | Vapor ignition can burn you and blow out glass doors | Wax fire starters, dry kindling, fatwood |
Settle the firewood question before winter. Our guide to the best firewood for Colorado covers which local species burn hot and clean and how to tell if a load is truly seasoned.
Preparing Before the Season
Spend an afternoon in October on this list. It is the one we give our own families.
- Book a sweep and an inspection before the first storm. A flue full of creosote or a nest in the cap is not something to discover by firelight. Our chimney sweep and cleaning service and a chimney inspection cover both and tell you whether the damper, cap and liner are up to a week of steady burning.
- Learn your damper. Find the handle and shine a flashlight up the throat to confirm it moves. Stuck dampers are common in older brick homes.
- Stage the wood. A week of dry, split wood under cover near the door, and two days' worth inside when a storm is forecast.
- Stock kindling and starters. Wax starters, strike anywhere matches in a sealed jar and a long lighter near the mantel.
- Headlamps, not candles. Fresh batteries in two headlamps kept in the fireplace room.
- Test the alarms. A battery CO alarm and a smoke alarm in the fireplace room.
- Service the gas fireplace. Fresh backup batteries and a test light with the breaker off.
- Set up the ash kit. Metal bucket with a tight lid, metal shovel and gloves, where you can find them in the dark.
- Keep an ABC fire extinguisher in the room.
- Write down the numbers. Utility outage line, gas emergency line, and where your gas and water shutoffs are.
Our winter chimney safety checklist expands on this list. One more Colorado note: some of the longest shutoffs now land on dry, windy red flag days. On those days burn gas rather than wood if you can, and make sure the cap has an intact spark arrestor screen.
Handling Ash and Embers in the Dark
Coals buried in ash stay hot for days, and in the dark it is easy to shovel a live ember into the wrong container. Use a headlamp, shovel only into a metal bucket with a metal lid, and if you can wait until daylight to clean the firebox, wait. Our guide on fireplace ash disposal safety covers the container, how long ash needs to sit, and where the bucket lives outside in Front Range wind.
Frequently Asked Questions
Can I use my gas fireplace when the power is out?
Usually, yes. A standing pilot millivolt fireplace works normally except for the blower. An electronic ignition fireplace works if it has a battery backup with fresh batteries or a manual pilot mode. Test it in the fall with the breaker off.
Will an open fireplace heat my whole house during an outage?
No. An open fireplace is a one room heater at best, with typical efficiency around ten percent or less. It sends heated air up the chimney and pulls cold air into the rest of the house. Close the room off and plan on one warm room.
Is it safe to sleep with the fireplace going overnight?
Not with open flames and nobody awake. Let the fire burn down to coals, close the screen or glass doors, leave the damper open, and keep a battery CO alarm in the room. A wood stove with the door latched can hold a low fire overnight if it is designed for it.
Can I run a pellet stove on a generator or battery?
Yes, with the right setup. Pellet stoves need power for the auger, igniter and exhaust fan. A battery backup unit sized for the stove, or a generator connected through a proper transfer switch, will run it. Never run the generator indoors.
Why is my fireplace smoking more than usual during a storm?
Wind and a cold flue. Gusts create downdrafts, a snow packed cap can block the flue, and a chimney that has sat cold for hours does not draft until it warms up. Start with a small, hot kindling fire and crack a nearby window. If smoke keeps coming in, let the fire die and have the chimney checked.
How much firewood do I need for a 24 hour outage?
Plan generously. An open fireplace burning steadily can go through a wheelbarrow load or two of split wood in a day, and a wood stove uses considerably less for more heat.
Get Your Fireplace Outage Ready Before the First Storm
The families who ride out a Colorado outage comfortably are the ones who checked the damper, swept the flue, tested the gas fireplace on batteries and stacked dry wood by the door in October. If you have not done that yet, call Adam Chimney Sweep at (720) 207-9232 to schedule a sweep, an inspection or a gas fireplace service visit, and we will make sure the fireplace you are counting on is ready.
